Scottish City Region and Growth Deals: Carbon Management Guidance for Projects and Programmes

5. Carbon Management Procedure

An appropriate methodology for managing and minimising whole life carbon emissions resulting from projects should be applied from the earliest possible stage, i.e. the Royal Institute of British Architects (RIBA) Stage 1 (Preparation and Briefing). The intended carbon management methodology should be stated within the Management Case section of the business case.

Where carbon reduction targets are set, they should promote carbon reduction on a whole life basis. A reduction target is a value lower than a baseline, as distinct from a ‘project target’ which is the principal value included in financial or economic calculations. The project owner can choose to set separate targets for Capital, Operational or User Carbon, or a single Whole Life Carbon target. For reference, projects in the North Wales Growth Deal are required to target a 40% reduction in embodied carbon and net zero operational carbon.

The following two methodologies are internationally acknowledged as best practice approaches for managing whole life carbon for buildings and infrastructure projects. They are mutually compatible and provide a ‘level playing field’ for the assessment and management of projects across the Deals programme. Both approaches originate from the need to minimise whole life carbon in the built environment to meet national statutory climate change targets.

5.1 Infrastructure: PAS 2080:2023 – Carbon Management in the Built Environment

PAS 2080:2023 is the UK’s principal specification for system-level carbon management across the whole built environment, replacing the 2016 infrastructure-only edition. All applicable Deal projects must apply PAS 2080:2023 from the earliest stage.

PAS 2080 stems from HM Treasury’s Infrastructure Carbon review in 2013, which identified that most carbon emissions in the UK (53% in 2013) are associated with the construction, operation, maintenance and use of infrastructure.

PAS 2080 emphasises the importance of all parties involved across the value chain working collaboratively towards a common carbon reduction goal and the achievement of the following outcomes:

• Reduced carbon, reduced cost infrastructure;
• More collaborative ways of working that promote innovation, delivering benefit to society and communities served by economic infrastructure;
• Effective carbon management in infrastructure that makes an important contribution to tackling climate change and leaves a positive legacy for future generations; and,
• The delivery of more sustainable solutions, at lower cost, that will enhance the reputation of the infrastructure industry, generating pride for those who work in it and attracting new people and skills.

Key requirements for projects include:

• Identifying carbon reduction opportunities across the whole value chain, including designers, suppliers, contractors and operators.
• Defining whole-life carbon targets aligned to Scotland’s net zero trajectory.
• Demonstrating application of the PAS 2080 mitigation hierarchy: Avoid - Switch - Remove.
• Incorporating carbon outcomes and KPIs into procurement, including use of the New Engineering Contract (NEC) X29 Climate Requirements clause where appropriate.
• Using BECD factors and benchmarks or equivalent for estimation and reporting.
• Providing transparent reporting across the project lifecycle, including evidence of continuous improvement.

5.2 Buildings: RICS Professional Statement

The RICS Whole Life Carbon Assessment (WLCA) for the Built Environment – 2nd Edition (2024) is the required methodology for Deals building projects. WLCA v2 aligns with EN 15978:2023 and requires consistent reporting across A1–C4 life-cycle stages, integration with BECD, and standardised evidence outputs.

The RICS WLCA is compatible with other approaches to building sustainability, e.g. BREEAM and the Net Zero Public Sector Buildings Standard (described within Section 5.4).

The RICS whole life carbon approach identifies the best overall combined opportunities for reducing carbon and helps to avoid any unintended consequences of focusing on operational emissions alone. The specific objectives of the RICS Professional Statement are to:

• Provide a consistent and transparent whole life carbon assessment implementation plan and reporting structure for built projects in line with EN15978 (Sustainability of construction works. Assessment of environmental performance of buildings. Calculation method);
• Enable coherence in the outputs of whole life carbon assessments to improve the comparability and usability of results;
• Make whole life carbon assessments more ‘mainstream’ by enhancing their accessibility and therefore encourage greater engagement and uptake by the built environment sector;
• Increase the reliability of whole life carbon assessment by providing a solid source of reference for the industry;
• Promote long-term thinking past project practical completion, concerning the maintenance, durability and adaptability of building components and the project as a whole; and,
• Promote circular economic principles by encouraging future repurposing of building components, as well as of the project as a whole, through quantifying their recovery, reuse and/or recycling potential.

5.3 Revenue Projects

The approach to managing carbon on projects where no construction is planned will depend on the objectives of the project and its purpose in relation to addressing the climate emergency.

The carbon emissions impact of some revenue projects will not be possible to meaningfully quantify according to Green Book requirements. However, such projects may still support the achievement of the transition to net zero emissions, e.g. through raising awareness or carbon literacy training. If this is possible and intended, it should be described in the Management Case.

Where any quantifiable carbon emissions impact from a revenue project is expected, this should be estimated in accordance with Green Book requirements and included in the economic case. In all such quantifiable cases, the same general best practice carbon management approach described in PAS 2080 (and RICS) should be applied, i.e. quantification, baselining, reduction targeting, and proactive management.

5.4 Current and Forthcoming Carbon Management Tools

A range of tools, standards and methodologies now underpin best practice in carbon assessment and management across the Scottish City Region & Growth Deals portfolio. The following resources represent the most relevant instruments currently in use or emerging across the built environment sector and should be applied, where appropriate, to ensure consistent and authoritative carbon management across all Deal projects.

PAS 2080:2023 – Carbon Management in the Built Environment: PAS 2080:2023 provides the UK’s principal specification for managing carbon across the whole built environment, covering both buildings and infrastructure. This updated edition expands significantly on the original 2016 infrastructure-only standard, emphasising system-level carbon governance, collaborative value-chain engagement, and outcome-driven carbon reduction. It establishes clear expectations for setting whole-life carbon targets, embedding the mitigation hierarchy into design and delivery, and aligning commercial requirements with carbon performance. The standard also reinforces the requirement for transparent reporting across all lifecycle stages and for procurement processes to enable low-carbon innovation, including through contract mechanisms such as NEC X29.

RICS Whole Life Carbon Assessment for the Built Environment – 2nd Edition (2024): This document sets out the UK’s most widely used methodology for calculating and reporting whole-life carbon emissions from buildings and other constructed assets. The 2024 revision aligns with EN 15978:2023 and the Built Environment Carbon Database, ensuring consistent reporting boundaries across Modules A–C and improved comparability between projects. The methodology is now the default standard for Scottish public sector bodies undertaking carbon assessments, providing detailed guidance on quantifying embodied and operational emissions, documenting assumptions, establishing baselines, and demonstrating reduction strategies.

Built Environment Carbon Database (BECD): The BECD is the UK’s national open-access database for embodied and operational carbon data from construction products and built assets. Developed collaboratively by professional institutions including RICS, ICE and CIBSE, and supported by industry partners, the database provides authoritative benchmark datasets and verified emissions factors for early-stage estimates, detailed assessments and post-construction reporting. BECD also enables consistent project-level data uploads, supporting transparency, benchmarking and the improvement of national carbon performance over time. All Deals projects undertaking whole-life carbon quantification should use BECD as their primary data source where applicable.

NEC X29 – Climate Change Contract Clause: The NEC X29 clause introduces formal climate change requirements into construction and infrastructure contracts, enabling clients to set measurable carbon reduction outcomes, performance indicators, and reporting obligations through procurement. Since its publication in 2022, X29 has become widely adopted across the UK public sector, reflecting the growing recognition that procurement is central to achieving net zero. The clause allows for the inclusion of carbon targets, monitoring frameworks, verification processes, compensation events, and incentive mechanisms, ensuring carbon performance is embedded contractually from tender to completion.

Net Zero Public Sector Buildings Standard (NZPSBS): This voluntary Standard supports public bodies in Scotland in meeting their net zero commitments for new build and major refurbished infrastructure projects. Developed by the Net Zero team at the Scottish Futures Trust, with input from Zero Waste Scotland, Health Facilities Scotland, and a wide range of public sector stakeholders, the Standard establishes clear expectations for energy performance, operational emissions, embodied carbon, resilience, and overall building quality. The Standard is increasingly used across public sector capital projects and should be applied, where relevant, to Deal-funded developments.

New Build Heat Standard (2024): Under the NBHS, new buildings and qualifying conversions (with building warrants issued from that date) must not use direct-emission heating systems (e.g., gas or oil boilers) as their main heating or hot-water systems. For Deal-funded projects, NBHS continues to have strong implications for option appraisal, whole-life carbon modelling, and energy system design. In particular, it obliges early consideration of heating technology, renewable heating systems (e.g. heat pumps, heat networks), fuel type, and alignment with zero (or low) direct emissions requirements.

Local Heat & Energy Efficiency Strategies (LHEES): LHEES provide local authorities with comprehensive plans for heat decarbonisation and energy efficiency across their regions. These strategies set out zoning proposals, preferred low-carbon heat solutions, and long-term investment pathways for buildings and energy networks. Deal projects must demonstrate alignment with the relevant LHEES for their area, ensuring that proposed developments are compatible with local energy strategies, future heat infrastructure, and Scotland’s overarching net zero objectives.

PAS 3090 – Adaptation Pathways for Infrastructure (Forthcoming): PAS 3090 is being developed as a UK specification for adaptation pathways in infrastructure systems, supporting decision-makers to ensure assets remain functional and safe under future climate conditions. Although not yet published, the emerging framework emphasises stress-testing projects against different climate scenarios, embedding adaptive design principles, and ensuring long-term resilience. Deal project teams should monitor its development and anticipate the requirement to integrate adaptation analysis alongside carbon assessment, particularly for infrastructure with long design lives.